Shale distillation



Dec. 15, 1931. M. J. TRUMBLE SHALE DISTILLATION Filed NOV.l 24, 1924 HT'TOZNEY Patented Dec. 15, 1931 UNITED vSTATES PATENT oFFicE MILON I. TRUMBLE, OF LOS ANGELES, CALIFORNIA,4 ASSIGNOR, BY MFSNE ASSIGN- MENTS, TO GOALS AND CHEMICALS LTD., XA CORPORATION OF NEVADA Snam: nIsrILLArIoN Application tiled November 24, 1924. Serial No. 751,865.

This inventionrelates to a process for the recovery of volatile hydrocarbon materials from solid bituminous substances, such as coal, oil shale or the like, hereinafter' referred to as solid carbonizable material and a preerred form of apparatus for eii'ecting this process. It is the primary object of this invention to produce a process of this character in which a super-heated vapor, preferably steam, is em loyed as the distilling medium.

It is Well {nown to the art, that from the standpoint of chemical eiiiciency, in the extraction of volatile carbon materials from solid bituminous substances, that steam has particular value as a distilling medium and numerous processes have been devised for the purpose of utilizing this particular property of steam in the distillation of coal, etc. From the standpoint of thermal efficiency however, steam as commonly used in very costly due to the tact that the majority of the heat content of the steam is in the form of latent heat of vaporization which is lost immediately upon the condensation of the steam. For this reason the use of steam in the distillation of bituminous materials has not been considered 'as economically sound and has therefore not come into the general practice.

The process which forms the subject matter of this application, is designed to use steam under superatmospheric pressure in a manner such that the latent heat content of the steam may be considered as being used repeatedly for the treatment' of a lurality of bodies of material being treate This is accomplished by treating the material in a series of separate retorts passin the same vapor from one retort to another t roughout the series and providing individualsuperheaters between the individual retorts'for the purpose of raising the temperature of the vapor above the condensation point corresponding to the pressure conditions in the system so that at no time is the latent heat of vaporization given up due to the condensation of the Water vapor present.

It is a noteworthy feature of this rocess that the mixture of water vapor and ydrocarbon vapor which are present after the steam has passed through the rst retort, has

volatiles of the solid bituminous materiali.

which is even greater than that of pure superheated steam. This is a feature both of novelty and utility, which is stressed at this point to emphasize the value of this process.

As was mentioned above, this invention also embraces a preferred form of apparatus for carrying out the above mentioned process and it is a noteworthy feature of this apparatus that it is adapted to increase the thermal eiiciency of the process `by taking advantage of the carbon content in the spent shale to provide the heat for super-heating the steam and mixture of steam and Volatile hydrocarbons. This'feature is accomplished by conducting the so-called spent shale from the retorts into a suitable furnace which contains the mentioned superheaters and in which the carbon contained in the spent shale is burned) bv iniecting a blast of air through the shale. i

The p-rocess forming the subject matter of this application andthe details in the referred form of apparatus by means of W ich this process may be carried' out, Will be better understood from the following description of the accompanying drawing in which the iigure is' a diagrammatic illustration showing a unit designed for the distillation of coal or shalein accordance with my process.

More particularly describing the invention l as herein illustrated, reference numerals 1A, 1B and 1C indicate retorts Which are adapted to receive solid bituminous material, from a conveyor indicated by reference numeral 2.

- A hopper indicated by reference numeral A plurality of super-heaters corresponding substantially in number with the number 'of retorts used in the process, are positioned within the furnace 6, such superheaters being indicated by reference numerals 7A, 7B and 7C.

The super-heaters 7A, 7 B and 7C are connected with super-heater inlet headers 8A, 8B and 8C, each of which is provided with suitable valves generally indicated by reference numeral 9, through the adjustment of which super-heated steam may be delivered from any one of the super-heaters into any one of the retorts through inlet pipes generally indicated by reference numeral 10A, 10B and 10C. l

Each of the retorts 1A, 1B and 1C is provided With a vapor outlet pipe such pipes be ing indicated by reference numerals 11A, 11B and 11C respectively. These pipes are in turn connected with vapor outlet headers 12A, 12B and lQC, respectively, such headers being provided with valves generally .indicated by reference numeral 13, by means of which the vapors coming from the retorts may be directed to an intermediate superheater through the header 12A or 12B or to a vapor recovery plant not shown through the header indicated by reference numeral Steam is introduced into the system lthro-ugh a suitable header indicated by reference numeral 14 which is provided with valves- 15 by means of which the steam may be directed i-nto any one of the super-heaters 7A, 7 B or 7C.

. In order that the. spent shale delivered to the furnace 6 may be burned therein, it is preferable to provide a furnace with a suitable blower indicated by reference numeral 16, by means of which air is blown through the hot spent shale in the furnace, such air effecting the combustion of the fixed carbon in the shale.

For the purpose of more clearly understanding the operationof this process, the inlet and outlet headers of the retorts are shown in full and dot and dash lines, the full lines being used to indicate the course of vapors through the system. The dotted lines indicate that portion of the' headers which are closed from the system by means o f valves, and which provide alternative means for directing the steam and mixture of steam l' and vapors through the system.

In the operation of the process, all of the retorts of the system may be filled with solid bituminous material such ascoal, o-il shale or the like and steam is lintroduced into the system through the header -14. For the purpose of description, this steam will be considered Yas passing through the super-heater 7A into the header' 8A, from which it is introduced into retort 1A.

The super-heated steam permeates upwardly through the retorty in direct contact with the shale, distilling the solid hydrocarbons therefrom and with such hydrocarbons admixed with the steam, it -is introduced into the header 12A which carries it to they drocarbonl materials contained in the shale,

this efficiency exceeding that of super-heated steam alone.

The vapor mixtures coming from the retort 1B is recycled through the super-heater 7C from which it is introduced into the retort 1C which may be considered as forming the last of the series of any preferred.

number of retorts, each of which is preceded by a super-heating unit.

The vapor mixtures accumulating from the retort 1C is introduced into a recovery line 12C which takes the mixed vapors to a dephlegmating and condensing plant (not shown).

It willbe understood from the foregoing description that the invention comprises a process and an apparatus for effecting same in which the chemically eficient medium of super-heated steam is made practical from a thermal standpoint through the conserva:

tion of the latent heat in the steam, by providing super-heaters in the system at points between individual bodies of shale which are being treated, in a manner such that there is no loss of latent heat in the process through condensation of the steam. In the practical operation of this invention, using say 12 retorts, the cycle of operations iS carried out substantially as' described.

The vapor mixtures coming from the retort 1B is recycled through the super-heater 7C. from which it is introduced into the retort 1C which may be considered as forming the last of the series of any preferred number of retorts, each of which is preceded by a, superheating unit.

The vapor mixtures accumulating from the retort 1C is introduced into a recovery line 12C which takes the mixed vapors to a dephlegmating and condensing plant (not shown).

It will be understood from the. foregoing description that the invention comprises a rocess and an apparatus for effecting same in which the chemically efficient medium of super-heated steam is made practical from the standpoint of thermal eiiciency througlh the conservation of the latent heat in t e steam by providing super-heaters in the Asystem at points between individual bodies of shale which are being treated, in a manner such that there is no loss of latent heat in the process through condensation of the steam.

In the practical operation of this invention, using say 12 retorts, the cycle of operations is carried out substantiallyas described above. When the process is lcari'ied out in connection with coal, which carbonizes at substantially 1050 F., I employ steam under a pressure of Y100 lbs. per square inch at a temperature of lsubstantially 1100 F., and when the process is carried out in connection with shale, which carbonizes at al temperature of substantially 800 F., the steam temperature is substantiali ly 850 F., it being preferable to maintain a steam temperature substantially F. above the carbonization temperature ofthe material which is being treate It will be apparent to those familiar with the art, that the temperature employed is dependent upon the character of the material bein treated and the quality desired in the ucts from the treatment. For an economically sound process it is preferable that f the temperature be suitable for vapor phase cracking of the distillation vapors. This temperature is dependent upon the quality of the raw material, the quantity of steam employed and the pressure under which the process is carried out. As pointed out above by way of example, the temperature which I prefer to employ in treating coal is in the neighborhood of 1100 F., however, I do not limit myself to this temrature, since higher temperatures might found necessargofor vapor phase cracking of the hydrocar n vapors comin from other materials or under other conditions.

It will be unde'rstood that while I have herel in described and illustrated the 'rocess as being carried out in one preferre form of apparatus, that the same is not to be limited by the scope of the description above, but includes such changes .as may fairly come within the spirit of the appended claims.

I claim as my invention:

1. A process for distilling solid carbonizable material for the recovery of volatiles therefrom, which com rises: charging a series of retorts with said) shale; introducin superheated steam into direct contact wit said shale in one retort of said series; withdrawing the mixture of steam and volatile products of distillation from said retort, superheating said mixture only to the temperature suitable for vapor phase cracking of hydrocarbon vapors and introducing said superheatedmixture into direct contact with the shale in the next retort of said series.

2. A process for .distilling solid carbonizable material for the recovery of volatile hydrocarbons therefrom which comprises: treating said material in separate bodies with a mixture of superheated steam and volatile hydrocarbons, said mixture being permeated successively through separate bodies of said material and superheated only to a temperature suitable for vapor phase cracking of hydrocarbon vapors before each permeation to prevent the condensation of the steam.

3. An organization for the utilization of solid carbonizable -material embodying: a plurality of retorts adapted to receive charges of solid carbonizable material, said retorts being connected in series to form a substantially closed distillation system; inlet means for delivering a heated gaseous circulating Huid into direct contact with the solid car- /admixture with said circulating fluid from said retorts; and means for superheating said mixture of circulating iiuid and volathe hydrocarbons after the mixture passes through each successive retort of the-system. said superheating means comprising a furnace adapted to receive residual carbon from the solid carbonizable 'material in said retorts, and superheaters in said furnace connected individually in series between the respective retorts.

4. An organization for the utilization of solid carbonizable material embodying: a plurality of retorts adapted to receive charges of solid carbonizable material, said .retorts being connected in series to form a substantially closed distillation system; inlet means for delivering a heated gaseous circulating Huid into direct contact with the solid carbonizable material in said retorts; outlet v means for receiving volatile hydrocarbons in MILON J. TRUMBLE. 

